Printing system and control method thereof

ABSTRACT

In a printing system which feeds a sheet from a plurality of sheet storage units and prints an image on the fed sheet, and a control method thereof, when a sheet storage unit selected as a paper feed source does not store sheets of a size designated by a print job, and a sheet storage unit which stores sheets of the size designated by the print job does not exist in a group to which the selected sheet storage unit belongs, the user is notified of a sheet storage unit in the group as a sheet storage unit which should store sheets.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a technique for arranging, grouping, and using a plurality of sheet storage units.

2. Description of the Related Art

In an image forming apparatus including a plurality of paper feed cassettes (sheet storage units), these paper feed cassettes are grouped and handled. According to this technique, for an input print job which designates a given paper feed cassette, even if paper in the given paper feed cassette runs out, the print job can be executed by feeding paper from another paper feed cassette of a group to which the given paper feed cassette belongs.

Many companies have proposed methods for increasing the availability of an image forming apparatus by efficiently using a plurality of paper feed cassettes in a group. For example, there has been proposed a method of using first a paper feed cassette in which paper is left in a small amount, out of paper feed cassettes in a group, and notifying the operator of the absence of paper in advance to effectively supply paper (Japanese Patent Laid-Open No. 2009-256077).

However, when a print job requiring many paper sizes and paper types is executed and no necessary paper exists in a designated group, the operator cannot be instructed about a paper feed cassette of a paper size or paper type which should be changed.

Generally, when notifying the operator of the absence of paper, the operation panel highlights a paper feed cassette designated by the printer driver or a paper feed cassette selected by the paper feed cassette auto select function. In many cases, however, many print jobs frequently use a paper feed cassette which runs out of paper. If paper of a paper size or paper type which is rarely used but happens to be necessary for the current print job is loaded in the frequently used paper feed cassette, the paper in the paper feed cassette is highly likely to be replaced again for a subsequent print job. As a whole, paper replacement work increases.

SUMMARY OF THE INVENTION

An aspect of the present invention is to eliminate the above-mentioned problems with the conventional technology.

The present invention provides a technique of, when no target sheet exists in a sheet storage unit selected as a paper feed source, reliably notifying the user of an optimum sheet storage unit in which sheets should be replaced or set in a group to which the selected sheet storage unit belongs.

The present invention in its first aspect provides a printing system which feeds a sheet from a plurality of sheet storage units and prints an image on the fed sheet, comprising: a storage unit configured to store a size of a sheet set in each sheet storage unit of the plurality of sheet storage units; a registration unit configured to register, as one group, at least two sheet storage units out of the plurality of sheet storage units; a first print control unit configured to, in a case where a sheet storage unit selected as a paper feed source stores a sheet of a size designated by a print job, print an image on a sheet fed from the sheet storage unit; a second print control unit configured to, in a case where the sheet storage unit selected as the paper feed source does not store a sheet of the size designated by the print job, feed a sheet from a sheet storage unit which stores a sheet of the size designated by the print job within a group to which the selected sheet storage unit belongs, and print an image on the fed sheet; and a notification unit configured to, in a case where the sheet storage unit selected as the paper feed source does not store a sheet of the size designated by the print job, and a sheet storage unit which stores a sheet of the size does not exist in the group to which the selected sheet storage unit belongs, notify a user of a sheet storage unit in the group as a sheet storage unit in which a sheet is to be set.

The present invention in its second aspect provides a control method of controlling a printing system which feeds a sheet from a plurality of sheet storage units and prints an image on the fed sheet, comprising: a storage step of storing, in a storage unit, a size of a sheet set in each sheet storage unit of the plurality of sheet storage units; a registration step of registering, as one group, at least two sheet storage units out of the plurality of sheet storage units; a first print control step of, in a case where a sheet storage unit selected as a paper feed source stores a sheet of a size designated by a print job, printing an image on a sheet fed from the sheet storage unit; a second print control step of, in a case where the sheet storage unit selected as the paper feed source does not store a sheet of the size designated by the print job, printing an image on a sheet fed from a sheet storage unit which stores a sheet of the size designated by the print job within a group to which the selected sheet storage unit belongs; and a notification step of, in a case where the sheet storage unit selected as the paper feed source does not store a sheet of the size designated by the print job, and a sheet storage unit which stores a sheet of the size does not exist in the group to which the selected sheet storage unit belongs, notifying a user of a sheet storage unit in the group as a sheet storage unit which is to store a sheet.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram exemplifying the configuration of a printer control system according to an embodiment;

FIG. 2 is a functional block diagram showing a printer according to the embodiment;

FIG. 3 is a view exemplifying a screen display used in a paper feed cassette group setting unit;

FIGS. 4A and 4B are views showing display examples of guidance information generated by a paper replacement method guidance generation unit;

FIG. 5 is a flowchart for explaining paper replacement method guidance display processing by the printer according to the embodiment;

FIG. 6 is a flowchart for explaining paper size/paper type search processing in step S501 of FIG. 5;

FIG. 7 is a flowchart for explaining paper size/paper type change guidance generation processing in step S506 of FIG. 5;

FIG. 8 is a flowchart for explaining paper size/paper type switching recommended cassette search processing in step S701 of FIG. 7; and

FIG. 9 is a flowchart for explaining cassette guidance generation processing for another group in step S702 of FIG. 7.

DESCRIPTION OF THE EMBODIMENTS

Preferred embodiments of the present invention will now be described hereinafter in detail, with reference to the accompanying drawings. It is to be understood that the following embodiments are not intended to limit the claims of the present invention, and that not all of the combinations of the aspects that are described according to the following embodiments are necessarily required with respect to the means to solve the problems according to the present invention. The same reference numerals denote the same building components, and a repetitive description thereof will be omitted. The embodiment will explain a printer control system as an embodiment of the printing system.

FIG. 1 is a block diagram exemplifying the configuration of the printer control system according to the embodiment.

Referring to FIG. 1, a client PC 120 inputs a print job to a printer 100 via a network I/F 106. The client PC 120 receives the notification of a status change of the printer 100, and the progress of a print job via the network I/F 106. The printer 100 includes a main controller 112 for controlling the printer 100, and a printing unit 110. Although not shown, the printing unit 110 includes a printing mechanism, mechanical components such as a sensor, an electrical circuit for controlling them, and software.

The printing unit 110 and main controller 112 are connected by a printing unit I/F 107, and can transmit video signals for image formation and read out sensor values representing the remaining amount of paper and the like. A CPU 101 is the center of the main controller 112. The CPU 101 implements a print operation by controlling the printing unit 110 while reading out from and writing data in a RAM 102 in accordance with a control program stored in a program ROM 104. The main controller 112 also includes a font 103 for expressing a character, and a data ROM 105 for saving fixed values. An external memory 109 is used to save a large amount of data such as image data. The external memory 109 also stores optional software and the like (not shown). An operation unit 108 includes input keys for accepting an instruction from the operator by the printer 100, and a display unit for displaying the state of the printer 100.

FIG. 2 is a block diagram showing the functional arrangement of the printer 100 according to the embodiment.

A paper feed storage unit 201 and printing process unit 208 are hardware units of the printing unit 110. More specifically, the paper feed storage unit 201 includes a plurality of paper feed cassettes (sheet storage units) which store paper (sheets). The printer 100 includes a plurality of paper feed cassettes, and can store a large amount of sheets and print on a large amount of sheets without stopping the print operation. Each paper feed cassette includes a remaining paper amount sensor, and can detect the absence of paper and the remaining amount of paper in the paper feed cassette. There are a plurality of types of remaining paper amount sensors, including one which detects a paper level from the side using a reflective sensor, and one which measures the moving amount of a tray for moving up a paper bundle for paper feed. The printing process unit 208 generates an image by an electrophotographic process or the like on paper supplied from a paper feed cassette of the paper feed storage unit 201 that is designated by a job control unit 207 of the main controller 112. The printing process unit 208 and job control unit 207 are important function components of the main controller 112, but are not directly relevant to the present invention and will not be described in detail.

A paper feed cassette group setting unit (sheet storage unit group setting) 202 and intra-group paper feed switching control unit 205 are implemented by software programs saved in the program ROM 104, and the CPU 101. The software programs notify the operator of information by displaying an image on a display unit 108 a of the operation unit 108. The printer 100 accepts an input from the operator using the key of the operation unit 108. More specifically, the paper feed cassette group setting unit 202 is a function of creating a paper feed group. The paper feed cassette group setting unit 202 groups paper feed cassettes in the paper feed storage unit 201 by using a user interface screen shown in FIG. 3 (to be described later). When a paper feed cassette during use runs out of paper, the intra-group paper feed switching control unit 205 determines, based on information of paper stored in the paper feed storage unit 201 and information of the paper feed cassette group setting unit 202, a paper feed cassette in the group from which a sheet should be supplied.

A paper replacement (sheet replacement) method guidance generation unit 204, paper replacement (sheet replacement) condition setting holding unit 209, and paper feed history storage unit 210 are also implemented by software programs saved in the program ROM 104, the CPU 101, the external memory 109, and the like. The main controller 112 stores a paper feed history in the external memory 109 (paper feed history storage unit 210) every time paper is fed from a paper feed cassette in the paper feed storage unit 201. The paper replacement condition setting holding unit 209 stores, in the external memory 109, a condition input by the operator via the operation unit 108. Based on these pieces of stored information, the paper replacement method guidance generation unit 204 creates guidance about a paper replacement method for displaying a screen as shown in FIG. 4A on the display unit of the operation unit 108. The contents of the guidance are, for example, the paper size of a paper feed cassette, the confirmed amount of paper in the paper feed cassette, paper feed cassette grouping information, and a paper feed cassette in which paper should be replaced.

FIG. 4A exemplifies the paper size and amount of paper stored in each of grouped paper feed cassettes. In this case, printing is done on A4-size paper and A3-size paper. Paper feed cassette 2 of group 1 stores A4-size plain paper, and paper feed cassette 2 is recommended as a paper feed cassette for storing A3-size paper. As will be described with reference to FIG. 3, paper feed cassette 1 of group 1 is a paper feed cassette preferentially used for other print jobs, and a change of its paper type and paper size is inhibited. Paper feed cassette 8 of group 3 stores A3-size plain paper. However, it is displayed that paper feed cassette 8 is not available because it belongs to another group.

FIG. 3 is a view exemplifying a screen display used in the paper feed cassette group setting unit 202.

In a printer including a plurality of paper feed cassettes, these paper feed cassettes are grouped and can be used as a large-volume paper feed cassette. That is, when one paper feed cassette in a given group becomes empty or a print job requests paper not stored in the paper feed cassette, paper in another paper feed cassette in the group is used. The printer can print continuously without stopping print processing.

The display unit 108 a of the operation unit 108 displays a group setting screen, and an item is selected based on an input from the touch panel of the operation unit 108.

A paper feed cassette list serving as an example of the paper feed storage unit 201 is displayed on the left side of the screen. The remaining amount of paper in each paper feed cassette is displayed as an icon, and the paper size and paper type are displayed as text. A check box representing whether sheet replacement is possible, and a pull-down choice are prepared beside each paper feed cassette. No check mark in the check box means that sheet replacement is possible. A check mark means that paper change is inhibited. A paper feed cassette with the check mark is excluded from paper feed cassettes serving as paper replacement candidates detected by a paper search unit 203. A pull-down list at the right end is used to designate a group to which each paper feed cassette is to belong. All paper feed cassettes are grouped based on designated group numbers.

In the example of FIG. 3, paper feed cassettes 1 to 3 are grouped into group 1. Paper feed cassettes 4 and 5 are grouped into group 2. Paper feed cassettes 6 to 8 are grouped into group 3. For the first paper feed cassettes (paper feed cassettes 1, 4, and 7) of the respective groups, their check boxes are checked to inhibit paper change.

A print job input from the client PC 120 designates a paper feed cassette to be used for the print job. When paper in the designated paper feed cassette runs out or when paper of a size or type not stored in the paper feed cassette becomes necessary, it is detected whether the necessary paper exists in a paper feed cassette in the same group as that of the designated paper feed cassette. If the necessary paper is detected in the group, the printer 100 continues the print job using paper in the detected paper feed cassette.

The operation of the printer 100 when there is no paper necessary for a print job is explained with reference to FIG. 4A. FIG. 4A is a view exemplifying a paper replacement guidance screen in which the display unit 108 a of the operation unit 108 displays guidance information generated by the paper replacement method guidance generation unit 204.

In this example, eight paper feed cassettes 1 to 8 are displayed. In correspondence with FIG. 3, paper feed cassettes 1 to 3 are classified into group 1, paper feed cassettes 4 and 5 are classified into group 2, and cassettes 6 to 8 are classified into group 3. In this example, a print job is a size-mixed job using A4 and A3 sizes. Since no A3-size paper exists in group 1, a paper out error occurs. This job requests the paper feed source to use group 1.

By referring to the display in FIG. 4A, the operator can cancel the error by changing the paper size of designated cassette 2 without hesitation.

FIG. 4B is a view exemplifying a paper replacement guidance screen when the paper feed cassette group setting unit 202 inhibits paper replacement of all paper feed cassettes in a group.

The screen is the same as that of FIG. 4A except for guidance at the top of the screen, and a description thereof will not be repeated. Since paper replacement is inhibited for all paper feed cassettes of group 1, the guidance prompts the operator to replace, with A3-size paper, paper in any paper feed cassette in group 1 designated by the job. In this example, it is considered that the printer 100 often receives jobs which use all the paper feed cassettes of group 1 for the A4 size. Hence, the main controller 112 displays a message to return to original A4-size paper in the changed paper feed cassette after the end of the print job using the A3 size during execution. Subsequent A4-size print jobs can be executed using all the paper feed cassettes of group 1.

A paper replacement method guidance display processing sequence by the main controller 112 according to the embodiment will be explained with reference to the flowchart of FIG. 5. Note that a program regarding this sequence for the main controller 112 is stored in the program ROM 104 or external memory 109 (for example, hard disk) of the main controller 112, read out into the RAM 102, and executed by the CPU 101.

FIG. 5 is a flowchart for explaining paper replacement method guidance display processing by the printer 100 according to the embodiment. This processing starts in a situation in which no necessary paper exists in a paper feed cassette designated by a print job while the main controller 112 processes the print job. This processing is achieved by executing, by the CPU 101, a program which is stored in the program ROM 104 and expanded in the RAM 102.

When a paper feed cassette designated by a print job stores paper of a designated paper size and paper type, printing is performed on the paper (sheet) fed from the paper feed cassette (first print control). When a paper feed cassette designated by a print job does not store sheets of a size and type designated by the print job, a paper feed cassette which stores sheets of the paper size and paper type designated by the print job is determined in the group. An image is printed on a sheet fed from the determined paper feed cassette (second print control).

In step S501, the main controller 112 searches a currently selected group for a paper feed cassette capable of storing paper of a paper size and paper type necessary for a print job. Details of the paper size/paper type search processing will be explained with reference to the flowchart of FIG. 6.

FIG. 6 is a flowchart for explaining the paper size/paper type search processing in step S501 of FIG. 5.

In step S601, the main controller 112 initializes a list for notifying a switching candidate paper feed cassette prior to processing. The process advances to step S602, and the main controller 112 determines, for all paper feed cassettes in a currently selected group, whether a paper feed cassette capable of storing a paper size and paper type requested by the print job exists in the group. If all the paper feed cassettes have not been checked, the process advances to step S603, and the main controller 112 reads out, from a paper feed cassette of the group, a paper size and paper type serving as attributes of the paper feed cassette. The paper size may be automatically detected from the position of a paper guide, or input by the operator using the operation unit 108. The paper type cannot be detected automatically, and thus is input by the operator via the operation unit 108. Then, the process advances to step S604, and the main controller 112 determines whether the paper size and paper type requested by the print job coincide with the attributes of the target paper feed cassette. If the paper size and paper type coincide with the attributes, the process advances to step S605, and the main controller 112 stores the number of the detected paper feed cassette in the switching candidate cassette list. Then, the process advances to step S606. If the main controller 112 determines in step S604 that the paper size and paper type do not coincide with the attributes, the process advances to step S606, and the main controller 112 changes the paper feed cassette to be checked to the next paper feed cassette. If all the paper feed cassettes have been checked in step S602, the main controller 112 notifies the calling source of the switching candidate cassette list, and ends the search processing.

Referring back to FIG. 5, in step S502, the main controller 112 determines, by referring to the switching candidate cassette list, whether a paper feed cassette coincident with the paper size and paper type exists in the current group. If the main controller 112 determines that a coincident paper feed cassette exists, the process advances to step S503, and the main controller 112 determines whether paper remains in the paper feed cassette. If paper remains, the process advances to step S505, and the main controller 112 continues the job by switching the paper feed cassette for use to the coincident paper feed cassette.

If the main controller 112 determines in step S503 that no paper remains in the paper feed cassette, the process advances to step S504, and the main controller 112 displays a message on the display unit 108 a of the operation unit 108 to prompt the operator to replenish the paper feed cassette with paper. After the paper feed cassette is replenished with necessary paper, the main controller 112 continues the interrupted print job.

If the main controller 112 determines in step S502 that a paper feed cassette coincident with the paper size and paper type does not exist in the current group, the process advances to step S506 to notify the operator to change the paper size and paper type of any paper feed cassette. For this purpose, the main controller 112 generates guidance representing a paper feed cassette which should store paper of the paper size and paper type necessary for the print job. Details of the generation processing will be described later with reference to the flowchart of FIG. 7. The process advances to step S507, and the main controller 112 displays the guidance obtained by the processing of step S506 on the display unit 108 a of the operation unit 108, and presents (notifies), to the user, a sheet storage unit capable of storing sheets of the designated size and type.

FIG. 7 is a flowchart for explaining paper size/paper type change guidance generation processing in step S506 of FIG. 5.

The guidance generation processing is roughly divided into two. First, in step S701, paper size/paper type switching recommended cassette search processing is performed. Details of this processing will be explained later with reference to FIG. 8. In general, the guidance is displayed to replace paper of a paper feed cassette designated by the client computer 120. In many cases, however, such a designated paper feed cassette is frequently used, so it is not preferable to change the paper size and paper type of the paper feed cassette. This is because, when another job is input, the paper size and the like of the paper feed cassette are highly likely to be changed again and the productivity of the overall apparatus may decrease.

Then, the process advances to step S702 to perform cassette guidance generation processing for another group. Details of this processing will be explained later with reference to FIG. 9. For a print job using a paper cassette group, paper is selected only within the same group. When paper necessary for the print job is stored in another group, the determination contents of the printer 100 are presented as guidance, and the operator of the printer 100 can execute the operation without confusion.

FIG. 8 is a flowchart for explaining the paper size/paper type switching recommended cassette search processing in step S701 of FIG. 7.

A paper feed cassette whose paper size and paper type are to be switched is preferably a paper feed cassette which is rarely used. First, in step S801, the paper feed cassette search order is changed using the paper feed frequency. The main controller 112 incorporates and uses the paper feed history storage unit 210 (FIG. 2) which stores a paper feed cassette, size, and paper count. In step S802, the main controller 112 determines whether all the paper feed cassettes of the paper feed storage unit have been checked. If all the paper feed cassettes have not been checked, the process advances to step S803. In step S803, the main controller 112 determines whether the paper feed cassette group setting unit 202 inhibits paper change of the paper feed cassette. If the main controller 112 determines that change is not inhibited, the process advances to step S806, and the main controller 112 interrupts the search, generates guidance to change paper of the paper feed cassette, and ends the processing.

If the main controller 112 determines in step S803 that change of the paper size and paper type of the paper feed cassette is inhibited, the process advances to step S804, and the main controller 112 adds display guidance representing that the paper feed cassette inhibits paper replacement. The process advances to step S805 to check the next paper feed cassette, and then to step S802.

If all the paper feed cassettes in the group have been checked in step S802, this group does not include a paper feed cassette capable of setting paper usable for the print job. In this case, the process advances to step S807, and the main controller 112 displays a message that this group does not include a paper feed cassette capable of setting paper usable for the print job. In this case, the user changes paper of any paper feed cassette in the group to the paper size or paper type designated by the print job, and continues the print job. At this time, the main controller 112 generates a message to prompt the user to return paper in the paper feed cassette to an original paper size and paper type set by the administrator after the end of the print job. A paper feed cassette number is substituted into “% d” used in a guidance character string in FIG. 8. A paper size name and paper type name are substituted into “% s”.

Although the determination of step S803 uses the paper change inhibition/permission setting value designated by the paper feed cassette group setting unit 202, it may use another condition. For example, when it is recognized in advance that a print job spooled in the main controller 112 uses a paper feed cassette, the use of the paper feed cassette may be inhibited.

FIG. 9 is a flowchart for explaining the cassette guidance generation processing for another group in step S702 of FIG. 7. This search processing is executed for all the paper feed cassettes of the printer 100.

In step S901, the main controller 112 determines whether all the paper feed cassettes of the printer 100 have been checked. If all the paper feed cassettes of the printer 100 have not been checked, the process advances to step S902, and the main controller 112 determines whether the paper feed cassette to be checked belongs to the same group as that of a paper feed cassette designated by the print job. Since the guidance for the same group has already been generated in the switching recommended cassette search processing described with reference to FIG. 8, the process advances to step S905. However, this processing targets only a paper feed cassette belonging to another group, and the process advances to step S903.

In step S903, the main controller 112 determines whether there is a paper feed cassette for which the same paper size and paper type as those requested by the print job are set. If there is a paper feed cassette for which the same paper size and paper type are set, the process advances to step S904, and the main controller 112 generates guidance representing that the paper feed cassette is not available because it belongs to a different group. After that, the process advances to step S905. If a paper feed cassette for which the same paper size and paper type are set does not exist in step S903, the process advances to step S905. In step S905, the main controller 112 targets the next paper feed cassette. The process returns to step S901 to continue the search.

The embodiment has made an explanation on the premise of a plurality of paper feed cassettes. However, the same effects can be obtained even when all paper feed cassettes are handled as one group.

The embodiment has explained the operation unit using the liquid crystal display unit and touch panel. However, the present invention is not limited to this technique. The same effects can be obtained even when, for example, a Web user interface is used via a network.

Other Embodiments

Aspects of the present invention can also be realized by a computer of a system or apparatus (or devices such as a CPU or MPU) that reads out and executes a program recorded on a memory device to perform the functions of the above-described embodiment(s), and by a method, the steps of which are performed by a computer of a system or apparatus by, for example, reading out and executing a program recorded on a memory device to perform the functions of the above-described embodiment(s). For this purpose, the program is provided to the computer for example via a network or from a recording medium of various types serving as the memory device (for example, computer-readable medium).

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2011-232117, filed Oct. 21, 2011, which is hereby incorporated by reference herein in its entirety. 

What is claimed is:
 1. A printing system which feeds a sheet from a plurality of sheet storage units and prints an image on the fed sheet, comprising: a storage unit configured to store a size of a sheet set in each sheet storage unit of the plurality of sheet storage units; a registration unit configured to register, as one group, at least two sheet storage units out of the plurality of sheet storage units; a first print control unit configured to, in a case where a sheet storage unit selected as a paper feed source stores a sheet of a size designated by a print job, print an image on a sheet fed from the sheet storage unit; a second print control unit configured to, in a case where the sheet storage unit selected as the paper feed source does not store a sheet of the size designated by the print job, feed a sheet from a sheet storage unit which stores a sheet of the size designated by the print job within a group to which the selected sheet storage unit belongs, and print an image on the fed sheet; and a notification unit configured to, in a case where the sheet storage unit selected as the paper feed source does not store a sheet of the size designated by the print job, and a sheet storage unit which stores a sheet of the size does not exist in the group to which the selected sheet storage unit belongs, notify a user of a sheet storage unit in the group as a sheet storage unit in which a sheet is to be set.
 2. The system according to claim 1, further comprising a paper replacement condition setting unit configured to designate, for each of the plurality of sheet storage units, whether sheet replacement is possible, wherein said notification unit notifies the user of the sheet storage unit for which sheet replacement is set to be possible.
 3. The system according to claim 1, further comprising a paper feed history storage unit configured to store a paper feed history of each of the plurality of sheet storage units, wherein said notification unit notifies a sheet storage unit having a low paper feed frequency preferentially as the sheet storage unit in which a sheet is to be set.
 4. The system according to claim 1, further comprising a paper replacement condition setting unit configured to designate, for each of the plurality of sheet storage units, whether sheet replacement is possible, wherein in a case where said notification unit notifies a sheet storage unit for which sheet replacement is set to be impossible as the sheet storage unit in which a sheet is to be set, said notification unit notifies the user of a message which prompts the user to return, after an end of the print job, a sheet of the sheet-replaced sheet storage unit to an original sheet.
 5. A control method of controlling a printing system which feeds a sheet from a plurality of sheet storage units and prints an image on the fed sheet, comprising: a storage step of storing, in a storage unit, a size of a sheet set in each sheet storage unit of the plurality of sheet storage units; a registration step of registering, as one group, at least two sheet storage units out of the plurality of sheet storage units; a first print control step of, in a case where a sheet storage unit selected as a paper feed source stores a sheet of a size designated by a print job, printing an image on a sheet fed from the sheet storage unit; a second print control step of, in a case where the sheet storage unit selected as the paper feed source does not store a sheet of the size designated by the print job, printing an image on a sheet fed from a sheet storage unit which stores a sheet of the size designated by the print job within a group to which the selected sheet storage unit belongs; and a notification step of, in a case where the sheet storage unit selected as the paper feed source does not store a sheet of the size designated by the print job, and a sheet storage unit which stores a sheet of the size does not exist in the group to which the selected sheet storage unit belongs, notifying a user of a sheet storage unit in the group as a sheet storage unit which is to store a sheet. 